React Native Engineer (f/m/d)

As a React Native Engineer at ITRex, you will build a self-custody crypto wallet for a major stablecoin company. You'll work on wallet creation and recovery, transaction signing, secure key storage, WalletConnect and EVM integrations. Keys are generated and kept on the user's own device in code already distributed through the app stores, so security and performance of the mobile layer are part of every feature, not a polishing step before release. You work day to day with Product, Design and Backend, and directly with external SDK vendors and third-party providers on integrations. This is a fully remote, long-term role.

What you'll do

• Architect, build, and maintain high-performance, scalable React Native applications for iOS and Android
• Collaborate with Product, Design, and Backend teams to define requirements and deliver new features
• Integrate and maintain third-party SDKs, native modules, and Web3/crypto libraries
• Implement Web3 functionality, including wallet features, signing, and smart contract interactions
• Ensure secure handling of sensitive data such as private keys and seed phrases, and enforce mobile security best practices
• Ensure top-level application performance, responsiveness, and overall app quality
• Identify and resolve performance bottlenecks, defects, and reliability issues
• Implement and maintain comprehensive test coverage including unit, integration, and end-to-end tests
• Work with CI/CD pipelines to support automated build, testing, and deployment processes
• Communicate and collaborate with external partners including banks, SDK vendors, and third-party providers to support integrations, resolve issues, and ensure technical alignment
• Research, evaluate, and introduce new technologies and best practices to improve product quality and development efficiency
• Participate in the full application development lifecycle from initial concept to production deployment

What you bring

• 3+ years of experience in mobile development with a focus on React Native
• Understanding of React Native architecture, preferably with exposure to Fabric and TurboModules
• Proven ability to architect, build and maintain high-performance, scalable mobile applications
• Expertise in application performance optimization, debugging, and profiling
• Knowledge of TypeScript and experience enforcing strict typing practices
• Experience publishing and maintaining apps in App Store and Google Play
• Expertise in identifying, analyzing, and resolving application bottlenecks and performance issues
• Experience building and maintaining robust testing strategies including unit, integration, and end-to-end testing
• Ability to research, evaluate, and introduce new technologies and best practices
• Strong understanding of mobile security principles, secure data storage, and anti-fraud mechanisms
• Upper-Intermediate English or higher

Nice to have

• Hands-on experience in crypto and blockchain development such as crypto wallets, signing, and transactions
• Strong understanding of Web3 technologies including WalletConnect, EVM networks, RPC, and smart contract interaction
• Experience with secure key storage, seed phrase handling, encryption, private key management, and cryptography best practices
• Experience integrating complex SDKs and APIs, bridging native iOS and Android SDKs, and working with Web3 and crypto libraries
• Understanding of ERC standards and token metadata structures

What we offer

• Remote flexibility to work where and how you work best
• Competitive salary plus benefits including medical, wellness, and learning
• Ownership opportunities to identify problems worth solving and own them
• Learning investment including English classes, professional development, and well-being support
• Career progression with real paths up
• Responsive teammates and a supportive culture where people help when you're stuck
• Regular meetups, tech talks, and human connections beyond work

About ITRex Group

ITRex is an AI company with 250+ people across the US and Europe building systems that work in the real world. They create solutions for companies like Procter & Gamble and Shutterstock, operating with openness, accountability, and a focus on doing good work together.